The present invention relates to phase error, and in particular, to phase error cancellation for differential signals in a quadrature architecture.
Many electronic applications utilize differential signaling. For example, some applications may use differential signals at low voltage levels to save power while delivering a reliable signal. However, as signal frequencies increase, problems arise in the propagation of differential signals between different circuits of an electrical device. For example, delivering reliable differential signals in communication electronics becomes problematic when employing phase modulation techniques at frequencies of 1 Gigahertz or greater. In particular, a system employing quadrature amplitude modulation (QAM) has an in-phase (I) differential signal and a quadrature phase (Q) differential signal which need to maintain a 90 degree phase difference. The layout of differential signal lines may cause signals to interfere with each other and may cause phase differences in the propagation of the signals. This may cause overall degradation in the signal quality and limit the performance of the application.
Thus, there is a need for improved phase separation. The present invention solves these and other problems by providing phase error cancellation for differential signals.